Stretchable 3D Printing In High Resolution | Digital Asia

In a study published in the Journal of Materials Chemistry B, a team of researchers at the Singapore University of Technology and Design (SUTD) and the Hebrew University of Jerusalem (HUJI), Israel, has developed highly stretchable hydrogels for high-resolution three-dimensional (3D) printing.

Hydrogels—hydrophilic networks of polymeric chains capable of retaining a large amount of water—have been widely used in a variety of applications. Recent advances in highly stretchable hydrogels have extended their applications into the fields of soft robotics, transparent touch panels and other applications requiring large deformation.

However, traditional fabrication methods, which mainly rely on molding and casting, confine the scope of applications. While 3Dprinting has been suggested as a method to increase the versatility of hydrogels, current 3D printing methods do not have sufficiently high printing resolution or geometric complexity, making them unsuitable for many applications.

To overcome these problems, the researchers developed a family of highly stretchable and ultraviolet light (UV)-curable hydrogels that can be stretched by up to 1,300 percent.

“We have developed the most stretchable 3D printed hydrogel sample in the world,” said SUTD study co-author Assistant Professor Ge Qi. “At the same time, the compatibility of these hydrogels with digital light processing-based 3D printing technology allows us to fabricate hydrogel 3D structures with resolutions up to 7 μm, and with complex geometries.”

The researchers also demonstrated that the printed stretchable hydrogels had excellent biocompatibility, which allowed them to directly 3D print biostructures and tissues. The optical clarity of these hydrogels also offers the possibility of 3D printing contact lenses.

More importantly, these 3D printable hydrogels can form strong interfacial bonds with commercial 3D printing elastomers, which allowed the researchers to directly 3D print hydrogel-elastomer hybrid structures, such as a flexible electronic board with a conductive hydrogel circuit printed on an elastomer matrix.

“Overall, we believe the highly stretchable and UV curable hydrogels, together with the UV curing based 3D printing techniques, will significantly enhance the capability of fabricating biostructures and tissue, contact lenses, flexible electronics and many other applications,” said Professor Shlomo Magdassi at HUJI, who is a co-author of the study.